[FIX] mail: self-author on 'Creating a new record...' message

Before this commit, when a record is in draft, the chatter message
"Creating a new record..." shown no author.

The intended showing is to display current user as author of this
message. Persona model requires `id` and `type`, the latter to
determine whether the persona is a guest or partner. Only the
id of current user was provided, so it was not enough to determine
the appropriate `Persona`.

closes odoo/odoo#144864

Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/static/src/core/web/thread_service_patch.js

@@ -107,7 +107,7 @@ patch(ThreadService.prototype, {
         if (id === false) {
             thread.messages.push({
                 id: this.messageService.getNextTemporaryId(),
-                author: { id: this.store.self.id },
+                author: this.store.self,
                 body: _t("Creating a new record..."),
                 message_type: "notification",
                 trackingValues: [],

addons/mail/static/tests/web/chatter_tests.js

@@ -312,6 +312,7 @@ QUnit.test("base rendering when chatter has no record", async () => {
     await contains(".o-mail-AttachmentBox", { count: 0 });
     await contains(".o-mail-Chatter .o-mail-Thread");
     await contains(".o-mail-Message");
+    await contains(".o-mail-Message-author", { text: "Mitchell Admin" });
     await contains(".o-mail-Message-body", { text: "Creating a new record..." });
     await contains("button", { count: 0, text: "Load More" });
     await contains(".o-mail-Message-actions");